Novel Insitu Cap_ULK Cap Structure with Maganese Silicate_SiCNH Dielectrics/Liner for Robust Linerless Nano Cu_Low K Interconnect
Publication Date: 2017-Jan-11
The IP.com Prior Art Database
Disclosed is a novel interconnect structure and associated method to improve the Cu resistance issue that impacts the nano Cu_low k interconnect. Furthermore, it improves the robustness of the Interlayer Dielectric (ILD) mechanical properties and Cu barrier.
Novel Insitu Cap _ULK Cap Structure with Maganese Silicate _SiCNH Dielectrics /Liner for Robust Linerless Nano Cu _Low K Interconnect
SiCNH dielectric has been used as cap, low k spacer, liner, etch stop, and hardmask (HM) for many device generations in Back End of Line/Front End of Line (BEOL/FEOL) production. Recent work shows that the SiCNH/p-SiCNH can be used in Cu interconnect to reduce liner thickness to sub-2nm. Forming the SiCNH/pSiCNH dielectric without a metal barrier can benefit Cu resistance at sub-10 nm Cu interconnect. Prior art discusses the formation of single stack cap/ulk SiCNH/pSiCOH or pSiCNH or other dielectric to minimize adhesion layer thickness and the formation of the BEOL stack without metal liner
This disclosure discusses a novel and robust Semiconductor Functional Block (SFB) Mn Silcate_SiCNH/SiCNOH BEOL stack structures and various combinations of ultrathin liners (sub-2nm) that enable a robust sub-10 nm BEOL Cu_Low k interconnect . The novel structures and associated processes are a significant improvement over the current fabrication process of ULK-Cap stack at various levels for sub-10 nm devices. The new structures and processes enable improved performance, lower fabrication cost, and improved reliability in sub-10 nm devices.
The novel contribution is a method to improve the Cu resistance issue that impacts the nano Cu_low k interconnect. Furthermore, it improves the robustness of the Interlayer Dielectric (ILD) mechanical properties and Cu barrier including:
• C-Rich SiCNH (k~3.3-3.4), or
• pSiCNH (k <= 2.8), or
• SiCNOH (k~< 3.1)or pSiCNOH (k <=2.6) dielectrics
The novel interconnect structure comprises:
• A device level
• At least a first wiring level and a second wiring level
• At least one via and one conductive line connecting the first wiring level to the second wiring level
• A dielectric stack between the first wiring level and the second wiring level comprising a first layer of silicon, carbon, nitrogen and hydrogen, and a second layer of silicon, carbon, nitrogen and hydrogen, wherein the first layer is dense (SiCNH)/SiCNO and the second layer is porous (pSiCNH)/pSiCNOH, or both layers can be dense or porous
• A dielectric liner between the SiCNH/p-SiCNH comprising Manganese, Silicon, Oxygen and Hydrogen (MnSixOyHz) or Manganese, Silicon, Carbon Oxygen, and Hydrogen (MnSixCyOzHq) or Manganese, Silicon, Oxygen, Carbon Nitrogen and Hydrogen (MnSixCyOzNwHq) or Manganese, Silicon, Nitrogen, and Hydrogen (MnSixNyHz) ,or Manganese, Silicon, Carbon,Nitrogen, and Hydrogen (MnSixCyNzHw)
The core novel components include:
• Low k ILD dielectric without metal barrier
• New ILD dielectrics with built-in Cu diffusion barrier and...